Effect of the liquid-to-powder ratio on physicochemical properties of calcium phosphate cements and of these properties over Biofilm thickness of adhered Staphylococcus Aureus

Abstract

Tricalcium phosphate (TCP) synthetized by high temperature solid state reaction at 1400°C and three derived calcium phosphate cements (CPCs) prepared at liquid to powder (L/P) ratios of 0.33, 0.44 and 0.55 ml/g, respectively, were physicochemically characterized. Calcium deficient hydroxyapatite crystals were identified by scanning electron microscopy on CPC, and differences in crystal sizes were observed at different L/P ratios. Also, the biofilm thickness of two Staphylococcus Aureus (S.aureus) strains grown for 24 hours on the three CPC are reported. A dependence of the biofilm thickness with the specific surface area (SSA) of CPC was identified. They are directly proportional for non-extracellular polysaccharide substances (EPS) producing S.aureus and inversely proportional for EPS producing S.aureus. Non-proportional behavior between the SSA and mechanical strength of the CPC was observed as L/P ratio increases.

Keywords

• calcium phosphate cement, tricalcium phosphate, Staphylococcus aureus, biofilm thickness, specific surface area, Extracellular polysaccharide substances